#include <DB/AggregateFunctions/AggregateFunctionFactory.h>
#include <DB/AggregateFunctions/AggregateFunctionGroupUniqArray.h>
#include <DB/AggregateFunctions/Helpers.h>

namespace DB
{

namespace
{

/// Substitute return type for Date and DateTime
class AggregateFunctionGroupUniqArrayDate : public AggregateFunctionGroupUniqArray<DataTypeDate::FieldType>
{
	DataTypePtr getReturnType() const override { return std::make_shared<DataTypeArray>(std::make_shared<DataTypeDate>()); }
};

class AggregateFunctionGroupUniqArrayDateTime : public AggregateFunctionGroupUniqArray<DataTypeDateTime::FieldType>
{
	DataTypePtr getReturnType() const override { return std::make_shared<DataTypeArray>(std::make_shared<DataTypeDateTime>()); }
};


static IAggregateFunction * createWithExtraTypes(const IDataType & argument_type)
{
		 if (typeid_cast<const DataTypeDate *>(&argument_type)) 	return new AggregateFunctionGroupUniqArrayDate;
	else if (typeid_cast<const DataTypeDateTime *>(&argument_type))	return new AggregateFunctionGroupUniqArrayDateTime;
	else
	{
		/// Check that we can use plain version of AggreagteFunctionGroupUniqArrayGeneric
		if (typeid_cast<const DataTypeString*>(&argument_type) || typeid_cast<const DataTypeFixedString*>(&argument_type))
			return new AggreagteFunctionGroupUniqArrayGeneric<true>;

		auto * array_type = typeid_cast<const DataTypeArray *>(&argument_type);
		if (array_type)
		{
			auto nested_type = array_type->getNestedType();
			if (nested_type->isNumeric() || typeid_cast<DataTypeFixedString *>(nested_type.get()))
				return new AggreagteFunctionGroupUniqArrayGeneric<true>;
		}

		return new AggreagteFunctionGroupUniqArrayGeneric<false>;
	}
}

AggregateFunctionPtr createAggregateFunctionGroupUniqArray(const std::string & name, const DataTypes & argument_types)
{
	if (argument_types.size() != 1)
		throw Exception("Incorrect number of arguments for aggregate function " + name,
			ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

	AggregateFunctionPtr res(createWithNumericType<AggregateFunctionGroupUniqArray>(*argument_types[0]));

	if (!res)
		res = AggregateFunctionPtr(createWithExtraTypes(*argument_types[0]));

	if (!res)
		throw Exception("Illegal type " + argument_types[0]->getName() +
			" of argument for aggregate function " + name, ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

	return res;
}

}

void registerAggregateFunctionGroupUniqArray(AggregateFunctionFactory & factory)
{
	factory.registerFunction("groupUniqArray", createAggregateFunctionGroupUniqArray);
}

}
